There are a few rules that come into play when you decide to set the price for your eBook:

1. It cannot be priced at $0.00. This is because each retail website charges a small service fee for the download of the eBook file. An eBook has to be at least $0.99 in order to be sold on any retail website.
2. Anywhere between $2.99 and $9.99 is considered an "acceptable" price. Research has shown that customers are more willing to purchase an eBook if it's priced significantly lower than a paperback or hardcover book.
3. Certain retailers will pay higher royalties if your eBook is priced between $2.99 and $9.99. For example, Amazon.com will pay out 70% of the retail download price as long as your eBook is between $2.99 and $9.99. If it priced above or below these margins, Amazon.com will only pay out 35% of the retail download price.
4. Take your audience into consideration. Will they be more willing to read your eBook if it's sold at a low price? Probably!
5. Do some research. Look at other eBooks that are in the same genre as yours. What price are they being sold for? Be competitive!